Internal mounted cylindrical turbine for electricity generation using exterior flush and scoop intakes

ABSTRACT

A method and system for generating electrical energy from wind are described. In an example, a method includes capturing wind in an intake on an exterior surface of a structure. The method also includes directing, via a duct, the wind from the intake to a centrifugal fan and, while directing the wind from the intake to the centrifugal fan, compressing and accelerating the wind in the duct. The method further includes receiving, in the centrifugal fan, the wind from the duct and rotating, via the received wind, a fan blade assembly in the centrifugal fan. The method still further includes generating electrical energy, via a generator, based on the rotation of the fan blade assembly.

CROSS REFERENCE TO RELATED APPLICATION

The present disclosure claims priority to and is a continuation of U.S.application Ser. No. 15/047,324, filed on Feb. 18, 2016, the entirecontents of which are herein incorporated by reference.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims and are not admitted to be priorart by inclusion in this section.

There is considerable interest in generating electrical power fromrenewable energy sources such as, for example, wind. Conventional windpower generation systems are typically provided in the form ofpropeller-type turbines, commonly referred to as windmills. In general,such systems include a plurality of long propeller blades mounted atop atall tower. When located in areas having sufficient wind velocity, thekinetic energy of the wind turns the propeller blades around a rotor.The rotor is coupled to a main shaft, which spins a generator to createelectrical energy.

Conventional wind power generation systems have a number of limitations.For example, conventional wind power generation systems generallyrequire large open spaces with relatively large wind velocities.Additionally, for example, conventional wind power generation systemscan be noisy, impact environmental aesthetics, and impact wildlife.

BRIEF SUMMARY

A method and system for generating electrical energy from wind isdisclosed. In an example, a method for generating electrical energy fromwind includes capturing wind in an intake on an exterior surface of astructure. The method also includes directing the wind, via a duct, fromthe intake to a centrifugal fan and, while directing the wind from theintake to the centrifugal fan, compressing and accelerating the wind inthe duct. The method further includes receiving, in the centrifugal fan,the wind from the duct and rotating, via the received wind, a fan bladeassembly in the centrifugal fan. The method still further includesgenerating electrical energy, via a generator, based on the rotation ofthe fan blade assembly.

In another example, a system for generating energy from a wind load on astructure includes an intake on an exterior surface of the structure.The intake is configured to capture wind on the exterior surface. Thesystem also includes a duct coupled to the intake at a first end of theduct. The duct is configured to direct the wind from the first end to asecond end of the duct. The duct is also configured to compress andaccelerate the wind directed from the first end to the second end. Thesystem further includes a centrifugal fan coupled to the second end ofthe duct for receiving the wind from the duct. The centrifugal fanincludes a fan blade assembly configured to rotate responsive to thewind received from the duct. The system also includes a generatorconfigured to generate electrical energy based on the rotation of thefan blade assembly.

These as well as other aspects, advantages, and alternatives will becomeapparent to those of ordinary skill in the art by reading the followingdetailed description with reference where appropriate to theaccompanying drawings. Further, it should be understood that thedescription provided in this summary section and elsewhere in thisdocument is intended to illustrate the claimed subject matter by way ofexample and not by way of limitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of a wind power generation systemaccording to an example.

FIG. 2 depicts a sectional top view of the example wind power generationsystem of FIG. 1.

FIG. 3 depicts a sectional side view of the example wind powergeneration system of FIG. 1.

FIG. 4A illustrates a perspective view of a centrifugal fan according toan example.

FIG. 4B illustrates a partial view of the example centrifugal fandepicted in FIG. 4A.

FIG. 5 depicts a perspective view of an example intake of the wind powergeneration system.

FIG. 6 depicts a perspective view of an example intake of the wind powergeneration system.

FIG. 7 depicts a perspective view of an example wind power generationsystem.

FIG. 8 depicts a flow chart for a method of generating electrical energyfrom wind according to an example.

FIG. 9 depicts a flow chart for a method of installing a wind powergeneration system in a structure according to an example.

FIG. 10 depicts a sectional top view of an example wind power generationsystem.

DETAILED DESCRIPTION

The disclosed methods and systems provide for generating electricalenergy from a wind load on a structure, e.g., a building, a bridge,and/or a tower. Although examples are shown in the Figures and describedbelow in the context of a building, it will be understood thatprinciples of the disclosure can extend to apply in other structuressuch as, for example, a bridge or a tower.

FIGS. 1-3 depict a wind power generation system 100 according to anexample of the disclosure. To more clearly depict aspects of the powergeneration system 100, FIGS. 1-3 are not to scale relative to eachother. As shown in FIG. 1, the power generation system 100 includes abuilding 102 having a plurality of exterior, lateral surfaces 104A-104Dand a roof 106. The building 102 can be, for example, a single-familyhouse, a low-rise building, a mid-rise building, and/or a high-risebuilding utilized for commercial, industrial, and/or residentialpurposes.

FIG. 1 further shows example wind 108 incident on and traversing theexterior surfaces 104A, 104B of the building 102. In general, when thewind 108 encounters the exterior surfaces 104A, 104B of the building102, the wind 108 is forced along the exterior surfaces 104A, 104Btowards respective corners 110 of the building 102. Additionally, due atleast in part to air pressure differences at the corners 110, the wind108 accelerates as it traverses along the exterior surfaces 104A, 104Btoward the corners 110. The wind incident on and traversing an exteriorsurface of a building may also be referred to as a wind load on thatexterior surface of the building.

The power generation system 100 advantageously captures such wind loadson the exterior surface 104A and directs the captured wind 108 to a windturbine 112 in an interior of the building 102 to generate electricalenergy. To capture wind 108 incident on and traversing the exteriorsurface 104A of the building 102, the power generation system 100includes an intake 114 on the exterior surface 104A. As shown in FIG. 2,the intake 114 provides an opening through which the wind 108 can passfrom the exterior, lateral surface 104A into an interior space of thebuilding 102. The intake 114 can have a size and shape that facilitatesdirecting the wind 108 into the building 102 with reduced (or minimal)air flow resistance. Example implementations of the intake 114 aredescribed below with respect to FIGS. 5-6.

In the example shown in FIGS. 1-2, the building 102 includes a singleintake 114 on one exterior surface 104A; however, as will be describedbelow, the building 102 can include multiple intakes 114 on one or moreexterior surfaces 104A-104D of the building 102 in other examples. Doingso can facilitate the power generation system 100 capturing greateramounts of wind 108 and thus generating greater amounts of electricalenergy.

As shown in FIGS. 2-3, the intake 114 is coupled to the wind turbine 112via an air duct 116. The air duct 116 includes one or more walls 120extending between a first end 116A coupled to the intake 114 and asecond end 116B coupled to the wind turbine 112. The one or more walls120 of the air duct 116 substantially or fully enclose an inner spacewithin the air duct 116. As such, the air duct 116 provides a conduitfor directing captured wind 108 from the intake 114 to the wind turbine112. In examples, the air duct 116 can have a circular, a rectangular, asquare, and/or a polygonal cross-sectional shape.

According to aspects of the disclosure, the air duct 116 compresses andaccelerates the wind 108 as it flows from the intake 114 to the windturbine 112. To do so, the air duct 116 includes one or more taperedsections, which taper inwardly toward an axis “A” of the air duct 116from the intake 114 to the wind turbine 112. In FIGS. 2-3, the air duct116 tapers continuously along an entire distance of the air duct 116.Tapering the air duct 116 over the entire distance of the air duct 116can help to reduce the angle of taper needed to achieve a particularextent of wind compression and acceleration, which in turn can helpminimize air flow losses. However, in other examples, the air duct 116can include one or more non-tapered sections in which thecross-sectional dimensions of the air duct 116 remain fixed over atleast a portion of the air duct 116. More generally, the air duct 116can be configured such that cross-sectional dimensions of the air duct116 are greater at the first end 116A than at the second end 116B and,in some implementations, greatest at the first end 116A and smallest atthe second end 116B. The duct 116 thus acts as a fluid mechanics nozzleto compress and accelerate the wind 108.

By compressing and accelerating the wind 108, the air velocity andthereby flow energy density is increased. This allows for more efficientelectrical energy generation by the wind turbine 112 described below.Additionally, compressing and accelerating the wind 108 via the duct 116can provide for more efficient use of interior space within the building102.

The air duct 116 can have a linear taper of varying degrees and shapesfor modifying the amount of wind 108 compression and/or acceleration. Inan example, the air duct 116 can have a linear taper of approximately 20degrees. The air duct 116 can be continuously tapered using amulti-power polynomial taper shape using a complex computational fluiddynamics (CFD) algorithm. Still other examples are also possible.

In FIGS. 2-3, the air duct 116 is shown as a straight run between theintake 114 and the wind turbine 112. That is, the air duct 116 does notinclude any elbows or turns. This can beneficially reduce or mitigateair flow resistance within the air duct 116. Optionally, the air duct116 can include one or more elbows or turns to provide greaterflexibility in the relative positioning between the intake 114 and thewind turbine 112 in the building 102. For instance, FIG. 10 illustratesan example power generation system 1000 including a duct 1016, whichturns between an intake 1014 and a wind turbine 1012.

As described above, the wind turbine 112 is coupled to the second end116B of the air duct 116. The wind turbine 112 converts the kineticenergy of the wind 108 received from the duct 116 into electricalenergy. To do so, the wind turbine 112 includes a centrifugal fan 122coupled to an electric generator 124. In particular, the wind 108received in the wind turbine 112 rotates a fan blade assembly 132 in thecentrifugal fan 122, which causes the electric generator 124 to generateelectrical energy. For example, the fan blade assembly 132 can becoupled to the electric generator 124 by a shaft 126 such that rotationof the fan blade assembly 132 rotates the shaft 126, which in turnrotates a rotor within a stator of the electric generator 124 togenerate electric energy. The fan blade assembly 132 and the rotor canrotate at the same speed (e.g., in a direct-drive configuration). Thewind turbine 112 can also include a gearbox (not shown) to step-upand/or step-down a speed of rotational coupling between the centrifugalfan 122 and the electric generator 124.

Utilizing the centrifugal fan 122 to convert the kinetic energy of thewind 108 to electrical energy provides a number of benefits. Forexample, the fan blades of a centrifugal fan 122 provide a greatersurface area per volume for the wind to act on relative topropeller-type turbines conventionally used for wind power generation.As a result, the wind turbine 112, which has the centrifugal fan 122,can generate electrical energy at lower wind speeds than similarly sizedpropeller-type wind turbines. Additionally, for example, a centrifugalfan 122 may be quieter to operate than a propeller-type wind turbine asair turbulence and turbine efficiencies directly relate to fan noise.

According to aspects of the disclosure, the electrical energy generatedby the wind turbine 112 can be provided to an electrical network withinthe building 102, an electrical power grid external to the building 102,and/or one or more energy storage devices 125 such as, for example, oneor more rechargeable batteries, thermal storage devices (e.g., moltensalts), flywheels, and/or superconducting magnetic coils. Thus, thegenerated electrical energy can be used to operate electrical deviceswithin the building 102 and/or stored for later use by such devices.

As shown in FIG. 3, the wind turbine 112 is further coupled to anexhaust duct 118, which facilitates egress of the wind 108 from thepower generation system 100. As the wind 108 passes through thecentrifugal fan 122, the wind 108 turns 90 degrees and exits thecentrifugal fan 122 via the exhaust duct 118. The exhaust duct 118 candirect the wind 108 from the centrifugal fan 122 to an exhaust opening144 in the building 102. For instance, in FIG. 1, the exhaust opening144 is on the roof 106; however, the exhaust opening 144 can be indifferent locations in other examples.

Optionally, the exhaust duct 118 can be coupled to a heating,ventilating, and air conditioning (HVAC) system 123 in the building 102.In this way, the wind 108 exhausted from the power generation system 100can be used to improve air flow in the HVAC system 123. This may, forexample, mitigate the need for booster fans in the HVAC system 123.

As described above, the wind turbine 112 includes a centrifugal fan 122.FIG. 4A illustrates a centrifugal fan 122 according to one example. Thecentrifugal fan 122 includes a fan blade assembly 132 in a housing 134.The housing 134 has an inlet 136 for receiving wind 108 from the airduct 116 and an outlet 138 for exhausting air to the exhaust duct 118.As shown in FIG. 4A, the inlet 136 is generally perpendicular to theoutlet 138.

FIG. 4B depicts the centrifugal fan 122 of FIG. 4A with a portion of thehousing 134 removed to expose the fan blade assembly 132. As shown inFIG. 4B, the fan blade assembly 132 includes a plurality of fan blades140 coupled to a hub 142. In FIG. 4B, each of the fan blades 140 curvesagainst a direction of rotation of the fan blade assembly 132 (i.e., ina “backward-curved” configuration). Alternatively, the fan blades 140can curve in the direction of rotation of the fan blade assembly 132(i.e., in a “forward-curved” configuration) or the fan blades 140 canextend from the hub 142 without curving (i.e., in a “straight radial”configuration). A fan blade assembly 132 having a backward-curvedconfiguration can provide for greater efficiency than a forward-curvedconfiguration or a straight radial configuration in someimplementations.

As described above, when wind 108 enters the inlet 136 from the air duct116, the wind 108 acts on the fan blades 140 of the fan blade assembly132. In particular, the wind 108 causes the fan blade assembly 132 torotate within the housing 134. The rotational energy of the fan bladeassembly 132 is transferred to the generator 124 (e.g., via the shaft126), which converts the rotational energy into electrical energy.Rotation of the fan blades 140 further applies a centrifugal force tothe wind 108, which forces the wind 108 out of the housing 134 via theoutlet 138.

In the illustrated example, the outlet 138 is coaxial with an axis ofrotation of the fan blade assembly 132 and the inlet 136 isperpendicular to that axis of rotation. However, the wind 108 can bereceived via the outlet 138 shown in FIG. 4A and exhausted via the inlet136. That is, the wind 108 can be received from the air duct 116 throughan opening parallel to the axis of rotation of the fan blade assembly132 and exhaust the wind 108 perpendicular to the axis of rotation ofthe fan blade assembly 132.

The centrifugal fan 122 can also optionally include a brake system 127to facilitate safe maintenance, repair, and/or upgrading of the powergeneration system 100. The brake system 127 can have a first state ofoperation in which the brake system is disengaged from the fan bladeassembly 132 to allow rotation of the fan blade assembly 132, and asecond state of operation in which the brake system 127 is engaged withthe fan blade assembly 132 to stop or prevent rotation of the fan bladeassembly 132. In this way, the brake system 127 can be selectivelyactuated between the first and second states to facilitate safe repairand/or maintain the power generation system 100.

As described above, the intake 114 captures wind incident on andtraversing the exterior surface 104A of the building 102. FIGS. 5-6depict example configurations for the intake 114, which can be utilizedin the power generation systems described herein (e.g., the powergeneration system 100). FIG. 5 depicts an example intake 514 on theexterior surface 104A of the building 102. As shown in FIG. 5, theintake 514 is formed as a recessed opening in the exterior surface 104A.In particular, the intake 514 has an inwardly sloping surface 528, whichforms the recessed opening in the exterior surface 104A. As furthershown in FIG. 5, when the wind 108 traversing the exterior surface 104Aencounters the intake 514, the wind 108 flows through a gap between thesurface 528 and the surface 104A to then pass into the duct 116.

In FIG. 5, the intake 514 is flush with the exterior surface 104A as noportion of the intake 514 protrudes outwardly from the exterior surface104A. By having a recessed intake 514, the intake 514 may have little orno negative impact on the aesthetics of the building 102. This may helpto reduce or eliminate a significant barrier to deploying wind powergeneration systems in buildings and urban environments.

As shown in FIG. 6, the intake 614 includes a scoop 630 that protrudesfrom the exterior surface 104A to facilitate capturing greater amountsof wind compared to a recessed-type intake 514. While a scoop-typeintake 614 may improve wind capture functionality, the protruding scoopmay be more noticeable to observers than a recessed-type intake 514.Yet, relative to the substantial space and size requirements ofconventional propeller-type wind turbines, the scoop 130 is relativelysmall and less likely to impact building aesthetics.

Optionally, the intake 114 can include aspects of both the recessed-typeintake 514 and the scoop-type intake 614. For example, the intake 114can include both an inwardly sloping surface (e.g., the surface 528) anda scoop (e.g., the scoop 630).

According to some aspects, the system 100 can also include an intakefilter 615 that is configured to inhibit solid objects (such as, forexample, birds, bats, insects, plastic bags, and garbage) from enteringthe intake 114, 514, 614. As examples, the intake filter 615 can includea grating, a mesh, netting, combinations thereof, and/or the like.Accordingly, the power generation systems of this disclosure maymitigate environmental impacts associated with collisions withconventional propeller-type wind turbines.

In the illustrated examples, the intakes 114, 514, and 614 are depictedas generally elongated in shape. This may help to capture greateramounts of wind load on the surfaces of the buildings using less (orminimal) interior space within the building 102. However, the intakes114, 514, 614 can be formed in other shapes according to other examples.Additionally, the intakes 114, 514, and 614 may be oriented in anyconfiguration relative to the vertical axis of the building. While theintakes 114, 514, and 614 are generally shown oriented parallel to avertical axis of the building, the intakes 114, 514, and 614 can beoriented differently relative to the vertical axis of the building.

In FIG. 1, the intake 114 is located at a corner 110 of the building102. Locating the intake 114 at a corner 110 of the building 102 canadvantageously facilitate capturing greater wind loads in the intake 114relative to other locations on the exterior surface 104 (e.g., due towind 108 accumulating and traversing over a greater surface area of theexterior surface 104); however, the intake 114 can be in differentlocations on the exterior surface 104 as shown in FIG. 7. Additionally,although the building 102 includes only one intake 114, duct 116, andwind turbine 112 in FIGS. 1-3, the building 102 can include more thanone intake 114, duct 116, and/or wind turbine 112. Integrating multipleintakes 114, ducts 116, and wind turbines 112 into the building 102 canprovide for capture of greater wind loads on the building 102 and, thus,greater electrical energy generation.

As noted above, the wind power generation system 100 can include anynumber of intakes 114, ducts 116, and wind turbines 112 in any locationon any surface of the building 102. As an example of this, FIG. 7depicts a power generation system 700 in which a building 702 includesmultiple intakes 714 at various locations on exterior surfaces 704 ofthe building 702. Also, in FIG. 7, one of the intakes 714 is located ona roof 706 of the building 702. As shown in FIG. 7, the size andorientation of at least some intakes 714 differs relative to other onesof the intakes 714. Also, as shown in FIG. 7, intakes 714′ are locatedand oriented so as to capture an updraft and a downdraft, respectively,on one of the exterior surfaces 704. The number, location, size, andorientation of the intakes 714, 714′ can be based on factors such as,for example, expected wind loads, space constraints within the building702 interior, and/or electrical energy generation needs of the building702. Although not shown, the system 700 can further include multipleducts, wind turbines, and exhaust ducts each coupled to a respective oneof the intakes 714 in a manner similar to that described above.

As illustrated and described above, each wind turbine receives wind froma single duct and a single intake; however, according to additional oralternative examples, a single wind turbine can receive wind frommultiple ducts and/or multiple intakes. In such examples, the system caninclude one or more features configured to facilitate mixing of the windreceived the different ducts and/or intakes so as to mitigate resistanceand/or other loses. For example, the system can include one or moredirectional slats in the air duct, which help to reduce turbulence ofair flow between the multiple air streams. By directing wind frommultiple intakes and/or ducts to a common wind turbine, even greateramounts of wind can be captured and directed to the wind turbine. Thismay help to achieve more efficient utilization of space within thebuilding for power generation.

As described above, the power generation systems of the presentdisclosure are generally located in an interior space of the building102. This provides a number of additional benefits and advantages overconventional propeller-type systems. For example, because the windturbine(s) are located in an interior space of the building 102, thepower generation systems of this disclosure address environmentalimpacts associated with conventional propeller-type wind turbines (e.g.,wildlife colliding with propellers). Additionally, by locating thecomponents of the power generation systems in an interior space of thebuilding 102, the systems can be easily, safely, and cost-efficientlyrepaired, serviced, and/or upgraded from that interior space of thebuilding 102. By contrast, conventional windmills are required to beplaced in open spaces exposed to potentially harsh and/or hazardousenvironmental conditions. Further still, locating the components of thepower generation systems in the building 102 helps to maintain buildingaesthetics.

Referring now to FIG. 8, a flow chart for an example method ofgenerating electrical energy from wind is depicted. At block 860, anintake captures wind on an exterior, lateral surface of a building. Atblock 862, a duct directs the captured wind from the intake to acentrifugal fan. At block 864, while directing the wind from the intaketo the centrifugal fan, the duct compresses and accelerates the wind. Atblock 866, after the wind has been compressed and accelerated in theduct, the centrifugal fan receives the wind from the duct. At block 868,the wind rotates a fan blade assembly in the centrifugal fan. At block870, responsive to the rotation of the fan blade assembly, electricalenergy is generated.

The flow chart illustrated in FIG. 8 is one example of a method forgenerating electrical energy from wind. The method of electrical energygeneration can omit steps, include additional steps, and/or modify theorder of steps presented above.

Referring now to FIG. 9, a flow chart for an example method ofinstalling a wind power generation system in a building is depicted. Insome implementations, the method may be carried out to retrofit anexisting building with the wind power generation system. Alternatively,the method may be carried out concurrent with construction of thebuilding.

At block 980, the method involves forming an intake in an exterior,lateral surface of the building. The intake can be formed, for example,by forming an opening in the exterior, lateral surface of the building.The opening can be sloped downwardly from the exterior, lateral surfaceof the building so as to provide a recessed intake. Optionally, formingthe intake can include coupling a scoop to the exterior surface at theopening.

At block 982, a wind turbine is installed in an interior space of thebuilding (e.g., a maintenance room). At block 984, a first end of theduct is coupled to the intake. At block 986, a second of the duct iscoupled to the wind turbine. In particular, the second of the duct canbe coupled to an inlet of a centrifugal fan in the wind turbine. Atblock 988, an outlet of the wind turbine is coupled to an exhaust ductconfigured to facilitate egress of the wind from the interior space inthe building. At block 990, a generator of the wind turbine iselectrically coupled to an electrical network of the building, anelectric power grid external to the building, and/or an energy storagedevice.

The flow chart illustrated in FIG. 9 is one example of a method forinstalling a wind power generation system in a building. The method ofinstallation can omit steps, include additional steps, and/or modify theorder of steps presented above.

Example aspects have been described above. After studying theconfigurations, examples, and arrangements described herein a skilledperson may come to understand, however, that changes and modificationsmay be made without departing from the true scope and spirit of thedisclosure. The description of the different advantageous aspects hasbeen presented for purposes of illustration and description, and is notintended to be exhaustive or limited to the form disclosed. Afterreviewing this disclosure, many modifications and variations will becomeapparent to those of ordinary skill in the art. Further, differentadvantageous aspects may provide different advantages as compared toother advantageous aspects. The example aspects selected are chosen anddescribed in order to best explain the principles of the disclosure, thepractical application, and to enable others of ordinary skill in the artto understand the disclosure with various modifications as are suited tothe particular use contemplated.

What is claimed is:
 1. A power generation system comprising: a windturbine in an interior of a building; an intake positioned on one of aplurality of exterior surfaces of the building to direct wind incidenton and traversing the one of the plurality of exterior surfaces of thebuilding to the wind turbine in the interior of the building, whereinthe intake is formed as a recessed opening in the one of the pluralityof exterior surfaces, wherein the intake has an inwardly sloping surfacewith respect to the one of the plurality of exterior surfaces that formsthe recessed opening and a gap between the inwardly sloping surface andthe one of the plurality of exterior surfaces; and an air ductpositioned in the interior of the building and coupling the intake tothe wind turbine, wherein gap of the intake passes wind into the airduct, wherein the air duct extends substantially parallel to the one ofthe plurality of exterior surfaces, wherein the air duct includes one ormore walls extending between a first end coupled to the intake and asecond end coupled to the wind turbine, wherein the one or more walls ofthe air duct substantially enclose an inner space within the air duct,wherein the air duct compresses and accelerates the wind as the windflows from the intake to the wind turbine.
 2. The power generationsystem of claim 1, wherein the air duct includes one or more taperedsections that taper inwardly from the first end to the second end. 3.The power generation system of claim 2, wherein the air duct taperscontinuously along an entire distance of the air duct.
 4. The powergeneration system of claim 2, wherein the air duct has a linear taper ofapproximately 20 degrees.
 5. The power generation system of claim 1,wherein the air duct is configured such that a cross-sectional dimensionof the air duct is greater at the first end than at the second end sothat the air duct acts as a fluid mechanics nozzle to compress andaccelerate the wind.
 6. The power generation system of claim 1, whereinthe air duct is a straight run between the intake and the wind turbinewithout any elbows or turns.
 7. The power generation system of claim 1,wherein the air duct includes one or more elbows or turns between theintake and the wind turbine.
 8. The power generation system of claim 1,further comprising: exhaust duct coupled to the wind turbine for egressof the wind.
 9. The power generation system of claim 8, furthercomprising: a heating, ventilating, and air conditioning (HVAC) systemin the building and coupled to the exhaust duct.
 10. The powergeneration system of claim 8, wherein the wind turbine comprises: ahousing; and a centrifugal fan with a fan blade assembly in the housing,wherein the housing has an inlet for receiving the wind from the airduct and an outlet for exhausting air to the exhaust duct, and whereinthe inlet is substantially perpendicular to the outlet.
 11. The powergeneration system of claim 10, wherein the centrifugal fan furthercomprises: a brake system having a first state of operation in which thebrake system is disengaged from the fan blade assembly to allow rotationof the fan blade assembly, and a second state of operation in which thebrake system is engaged with the fan blade assembly to stop or preventrotation of the fan blade assembly.
 12. The power generation system ofclaim 1, wherein the intake is flush with the one of the plurality ofexterior surfaces.
 13. The power generation system of claim 1, whereinthe intake further comprises: a scoop that protrudes from the one of theplurality of exterior surfaces to capture greater amounts of wind. 14.The power generation system of claim 1, further comprising: an intakefilter configured to inhibit objects from entering the intake.
 15. Thepower generation system of claim 1, wherein the intake is located at acorner of the building.
 16. The power generation system of claim 1,further comprising: multiple intakes on one or more of the plurality ofexterior surfaces of the building; and multiple air ducts positioned inthe interior of the building and respectively coupling the multipleintakes to the wind turbine.
 17. A method for generating electricalenergy from wind, comprising: capturing wind in an intake positioned onone of a plurality of exterior surfaces of a building, wherein theintake is formed as a recessed opening in the one of the plurality ofexterior surfaces, wherein the intake has an inwardly sloping surfacewith respect to the one of the plurality of exterior surfaces that formsthe recessed opening and a gap between the inwardly sloping surface andthe one of the plurality of exterior surfaces, wherein capturing thewind in the intakes comprises: receiving the wind into the recessedopening in the one of the plurality of exterior surfaces of thebuilding; and passing the wind from the gap into an air duct; directing,via the air duct positioned in an interior of the building and extendingsubstantially parallel to the one of the plurality of exterior surfaces,the wind from the intake to a centrifugal fan in an interior of thebuilding, wherein the air duct includes one or more walls extendingbetween a first end coupled to the intake and a second end coupled tothe centrifugal fan, wherein the one or more walls of the air ductsubstantially enclose an inner space within the air duct, wherein theair duct compresses and accelerates the wind as the wind flows from theintake to a wind turbine; receiving, in the centrifugal fan, the windfrom the air duct; rotating, via the received wind, a fan blade assemblyin the centrifugal fan; generating electrical energy, via a generator,based on the rotation of the fan blade assembly; and exhausting the windfrom the centrifugal fan in a direction that is perpendicular to adirection in which the wind is received in the centrifugal fan.
 18. Themethod of claim 17, wherein directing, via the air duct positioned inthe interior of the building, the wind from the intake to thecentrifugal fan in the interior of the building comprises: directing thewind through one or more tapered sections that taper inwardly from thefirst end to the second end.
 19. The method of claim 18, whereindirecting the wind through one or more tapered sections that taperinwardly from the first end to the second end comprises: directing thewind through a continuously tapered section along an entire distance ofthe air duct.
 20. The method of claim 17, capturing wind in the intakecomprises: capturing wind in the intake that is flush with the one ofthe plurality of exterior surfaces.